CHARACTERIZATION AND APPLICATION OF CROSS-LINKERS FOR POLYURETHANE AQUEOUS SYSTEMS - ISOPROPYLIDENE MALONATE-BLOCKED ISOCYANURATE

An adduct of hexamethylene isocyanurate and isopropylidene malonate wa s prepared and tested as a crosslinker in a one-pack water-borne polyu rethane system. It was characterized by FTIR, NMR, and SEC; the blocki ng and curing courses were followed by FTIR and DSC. The crosslinker w as a mixture of various oligomers having mainly amide-type linkages. T he cure analysis showed that cleavage of the malonate ring started at around 110 degrees C and was followed by the formation of ester-type p roducts. After 30 min of heating at 130 degrees C the insoluble part o f crosslinked polyurethane films exceeded 80%. (C) 1994 John Wiley and Sons, Inc.